1. Field of the Invention
The present invention relates to optical scanners generally and, more particularly, but not by way of limitation, to a novel, hand-held, optical indicia scanner and method of use, which scanner and method are particularly useful in scanning diffraction grating strips and laser-etched bar codes on silicon wafers in the field.
2. Background Art
Optical indicia scanners are widely used to read a variety of optical indicia and almost everyone is familiar with scanners used to read bar codes on products as they are purchased. Such optical indicia scanners may be fixed and the indicia to be read moved past the scanner or they may be hand-held and directed toward the indicia to be read.
A problem exists with hand-held such scanners when they are used to scan diffraction grating strips or bar codes etched on silicon wafers. In these cases, the reading head of the scanner must be held fairly perpendicular to the indicia being scanned and, particularly in the case of diffraction grating strips, it is necessary that the scanner be held fairly parallel to the major axis of the diffraction grating strip. This does not present a problem with fixed installations, since it is relatively easy to make sure that the reading head of the scanner is generally perpendicular to the indicia being scanned and that the path of the reading head is along the major axis of the scanner indicia. However, when it is desired to, for example, authenticate identifying indicia in the field, it is very difficult to properly align the scanner with the indicia being scanned.
Also, known hand-held optical indicia scanners generally include relatively complicated and expensive mechanisms and, thus, they are relatively expensive to manufacture.
Accordingly, it is a principal object of the present invention to provide an optical indicia scanner that is simple and that can be easily employed to scan diffraction grating strips and laser-etched bar codes on silicon wafers.
It is another object of the invention to provide such an optical indicia scanner and method that automatically place the reading head thereof generally perpendicular to the indicia being scanned.
It is an additional object of the invention to provide such an optical indicia scanner and method that facilitate the alignment of the scanner with the major axis of the indicia being scanned.
It is a further object of the invention to provide such an optical indicia scanner that is economical to manufacture.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figure.
The present invention achieves the above objects, among others, by providing, in a preferred embodiment, an optical indicia scanner, comprising: a housing; a light source disposed in said housing; a photodetector head disposed in said housing; and an optical indicia engaging, clear front plate disposed on said housing through which clear front plate said indicia is scanned when said optical indicia engaging, clear front plate is parallely disposed against said optical indicia.